Microchip MCP3202-CI/P 12-Bit Dual Channel ADC: Datasheet, Pinout, and Application Circuit Guide
The Microchip MCP3202-CI/P is a highly versatile, successive approximation (SAR) 12-bit analog-to-digital converter (ADC). This component is renowned for its excellent balance of performance, simplicity, and cost-effectiveness, making it a popular choice for a wide array of embedded systems and industrial applications. It communicates via the ubiquitous SPI serial interface, allowing for easy connection to microcontrollers (MCUs) and digital systems with minimal I/O pin requirements.
This guide delves into the MCP3202-CI/P's key specifications, pinout configuration, and a fundamental application circuit to help you integrate it seamlessly into your next design.
Datasheet Overview and Key Specifications
The datasheet for the MCP3202-CI/P provides a complete electrical and operational profile. Key specifications that define its performance include:
Resolution: 12-bit, providing 4096 (2^12) possible digital output codes.
Channels: Two differential or pseudo-differential input pairs (CH0, CH1). The device can be configured to accept two single-ended inputs effectively.
Supply Voltage: Operates from a single 2.7V to 5.5V power supply, compatible with both 3.3V and 5V logic systems.
Conversion Rate: A maximum sample rate of 100 kilosamples per second (ksps) at 5V.
Interface: SPI-compatible serial interface (using the CS, CLK, DIN, and DOUT pins).
Linearity: ±1 LSB maximum differential non-linearity (DNL) and ±1 LSB maximum integral non-linearity (INL).
Package: Available in an 8-pin PDIP (Plastic Dual In-line Package), denoted by the /P suffix, which is ideal for prototyping.
Pinout Configuration and Function
Understanding the pinout is critical for correct wiring. The MCP3202-CI/P comes in an 8-pin package:
1. CH0 (Pin 1): Analog Input Channel 0.
2. CH1 (Pin 2): Analog Input Channel 1.
3. AGND (Pin 3): Analog Ground. This is the ground reference for the analog circuitry.
4. VREF (Pin 4): Reference Voltage Input. The voltage applied here defines the analog input range (e.g., 0 to VREF). For best performance, decouple with a capacitor to AGND.
5. VSS/DGND (Pin 5): Digital Ground.
6. CLK (Pin 6): Serial Clock Input. The microcontroller drives this pin to shift data in and out.
7. DOUT (Pin 7): Serial Data Output. The ADC converts data on this pin, synchronized by the CLK.
8. CS/SHDN (Pin 8): Chip Select/Shutdown Input. A low signal on this pin activates the device. Bringing it high disables the device and resets the internal counters.
Basic Application Circuit Guide
A typical connection diagram for interfacing the MCP3202-CI/P with a microcontroller is straightforward. The circuit below demonstrates a standard single-ended input configuration.
Components Required:
Microchip MCP3202-CI/P ADC
Microcontroller (e.g., Arduino, PIC, ARM)
Power supply (3.3V or 5V)
A stable reference voltage source (can be the same as VDD)
Analog sensors (e.g., potentiometer, thermistor)
Wiring Steps:
1. Power: Connect VDD (Pin 5) to the MCU's positive supply (5V or 3.3V).
2. Ground: Connect both AGND (Pin 3) and VSS/DGND (Pin 5) to the system's common ground.
3. Reference Voltage: Connect VREF (Pin 4) to a stable voltage. For the full-scale input range, this can be tied to VDD.
4. SPI Communication:
Connect the MCU's CS (Chip Select) pin to the ADC's CS/SHDN (Pin 8).
Connect the MCU's SCK (Serial Clock) pin to the ADC's CLK (Pin 6).
Connect the MCU's MISO (Master In Slave Out) pin to the ADC's DOUT (Pin 7).
Connect the MCU's MOSI (Master Out Slave In) pin to the ADC's DIN (Pin 2). Note: Some simple software implementations may not require sending data to the ADC and this pin can be tied low, but it is standard to connect it.
5. Analog Input: Connect your analog signal source (e.g., the wiper of a potentiometer) to CH0 (Pin 1). The other terminal of the pot goes to VDD and GND.
Software Operation:
The MCU initiates a conversion by pulling CS low. It then toggles the CLK pin to:
Send a start bit, a configuration bit (to choose single-ended/differential mode and the channel).
Read the 12-bit conversion result on the DOUT pin, one bit at a time with each clock cycle.
ICGOODFIND: The MCP3202-CI/P stands out as a robust and straightforward solution for adding 12-bit analog sensing capabilities to digital systems. Its low power consumption, simple 4-wire SPI interface, and dual-channel input make it exceptionally adaptable for data acquisition tasks, from environmental monitoring to industrial control. Its availability in a DIP package further simplifies the prototyping and development process for engineers and hobbyists alike.
Keywords:
1. 12-Bit ADC
2. SPI Interface
3. Dual Channel
4. Application Circuit
5. Microcontroller Interfacing
